With the "Fade" sketch working properly I removed the LED and used the Arduino IDE to verify the "Blink" sketch so I could get the address of the temporary .hex file. Then I used the AVRdude command line to try and burn the "Blink" hex file to the ATtiny45. Again, I got the "programmer is not responding" error:
Attempt using "stk500v1" as programmer:
Roberts-MacBook-Pro:~ robertwinter$ avrdude -p t45 -P /dev/cu.usbmodemfa131 -c stk500v1 -U flash:w:/var/folders/d2/j8mp7t8j3ng3dgflw6j29c5w0000gn/T/build3844067978631596133.tmp/Blink.cpp.hex
avrdude: stk500_recv(): programmer is not responding
avrdude done. Thank you.
Attempt using "arduino" as programmer:
Roberts-MacBook-Pro:~ robertwinter$ avrdude -p t45 -P /dev/cu.usbmodemfa131 -c arduino -U flash:w:/var/folders/d2/j8mp7t8j3ng3dgflw6j29c5w0000gn/T/build3844067978631596133.tmp/Blink.cpp.hex
avrdude: stk500_recv(): programmer is not responding
avrdude done. Thank you.
After the AVRdude failed to burn the blink.hex file I plugged the LED back in and the "Fade" sketch is still running properly. Again, thanks for all the help. Hopefully I'm getting close to getting this thing to work.